The invention relates to a device for removing sputum (expectoration coughed up from the respiratory organs) from a tracheal catheter inserted into the trachea of a patient.
From U.S. Pat. No. 5,765,557 it is known that an increased amount of sputum collects in the lungs of patients having a tracheal catheter inserted into the trachea, which must be removed through regular suction. However, this known technique is extremely disadvantageous and considerably increases the danger of infections. The aforementioned US Patent therefore also provides for an airflow control device inside the patient in order to facilitate the removal of sputum from the patient""s inside without suctioning. The device contains a tubular duct that can be inserted into the patient and comprises a path for the inhalation as well as a separate path for the exhalation of air. The device further comprises an airflow control device on the inside, which is designed to control the air flowing in through the intake path for expanding the lungs of the patient and to permit the air that must be exhaled to flow through a separate exhalation path. The device is designed to remove the sputum for the patient by way of this exhalation path and the force of the air exhaled from of the lung.
The airflow control device, which is installed inside the patient, cannot be monitored from the outside, so that its error-free operation can only be assumed. Help needed during a malfunction frequently comes too late. For that reason, the device is not widely used in practical applications.
In practical operations, a tracheal catheter known from German Application 35 24 126 A1 therefore continues to be used in place of this device. The frontal end of this tracheal catheter can be inserted into the trachea, for example by making a cut in the trachea while a connecting piece that projects from the trachea is fitted onto the back end. For example, an air hose can be fitted onto this connecting piece for form a connection to a respirator or an air filter through which the patient is supplied with filtered, meaning germ-free respiratory air.
However, it has turned out that the cough frequently is so strong that the inserted air filter is clogged with sputum within a short time, often after less than ten minutes, such that the patient is gasping for air and must fight an asphyxia attack unless the filter is removed immediately and replaced with a new one. Since the patients are frequently paralyzed, for example by a stroke or brain seizure, they cannot remove the filter themselves, but depend on help from the nursing staff. As a result of the known shortage of nursing staff, patients frequently must depend on additional help from relatives and acquaintances. In reality, the filter is often simply omitted because staff does not have the time to replace it constantly. The patient then breathes in unfiltered air, which strongly increases the danger of contracting dangerous or even deadly infections.
It is the object of the invention to improve the known tracheal catheter, such that the sputum is automatically kept away from the air filter and can be removed without problems to avoid painful and agonizing asphyxia attacks by patients, as well as ban the danger of dying from asphyxia, even if the patient is left alone for a longer period of time, e.g. for several hours.
This object generally is solved according to the present invention by a housing
with a first opening, which can be connected to the tracheal catheter end that projects from the trachea;
with a second opening for exchanging exhaled air against filtered fresh air and
with a third opening for draining the sputum.
One advantageous modification of the invention provides a valve controlled by the respiratory air, which opens the third opening during the exhalation to allow sputum to drain out and closes this opening during the inhalation. It is advantageous if the housing is shaped like a cylinder, wherein the first opening is located in the bottom of the cylinder and the second and third openings are respectively located in its shell surface, essentially opposite each other, and the openings are provided with cylinder-shaped connecting pieces.
In order to connect the device to the tracheal catheter and to other apparatuses, it is furthermore provided that the inside wall of the connecting piece of the first opening has a conical shape and can be fitted onto the tracheal catheter end that projects from the trachea. The connecting piece of the second opening, which preferably points upward in the operating state, has a conical outside wall onto which an air filter for the inhaled air can be fitted. The connecting piece of the third opening, which preferably points downward in the operating state, has a conical outside wall onto which a catch bag for catching the sputum or a hose for draining the sputum to a catch bag can be fitted.
In the simplest case, the valve for opening and closing the third opening is realized as a pivoting flap that is controlled by the respiratory air, which flap opens the third opening during the exhalation, owing to the pressure of the exhaled air and counter to the pressure of a spring, its own weight or an additional weight, so that the sputum can flow out. This valve closes during the inhalation owing to the pressure of the spring, its internal weight or an additional weight.
According to another alternative for opening and closing the third opening, the valve is a piston controlled by the respiratory air. The valve opens the third opening during the exhalation for sputum to drain out, that is to say against the pressure of the exhaled air and against the pressure of a spring, its own weight, or an additional weight. During the inhalation, this opening is closed as a result of the pressure exerted by the spring, its own weight or an additional weight.
Further advantageous embodiments of the invention are mentioned in the additional dependent claims.
The advantages achieved with the invention in particular are that the sputum is automatically kept away from the air filter and can be removed without problems. Thus, the patient is spared painful attacks of asphyxia, and the danger of death by asphyxia is banned. The trouble-free operation of this device can be monitored at any time and at a glance, so that help can be rendered quickly in case of a possible malfunction.
The exemplary embodiment of the invention is shown in the drawing and is described in further detail below.